X-ray apparatus



Nov. 7, 1950 H. A. NEWMAN 11-1w APPARATUS Filed May 11, 194.9

INVENTOR. HERBERTA NEWMAN BY 2 Patented Nov. 7, 1950 X-RAY APPARATUSHerbert AhNewman, Delavan, Wis., assignor to The George W. BorgCorporation, Delavan, Wis., a corporation of Delaware Application May11, 1949, Serial N 0. 92,609

2 Claims.

The present invention relates in general to X-ray Apparatus, but more inparticular to X-ray tables which are equipped for spot film radiography.The object of the invention is a new and improved arrangement forenablingthe operator, when about to make a spot film radiograph, toquickly and accurately select the proper kilovoltage.

One factor which determines the kilo-voltage to be used is the distancebetween the film and the focal spot of the X-ray tube. In spot filmradiography the tube is supported beneath the table and while thedistance from the focal spot of the tube to the surface of the table topis fixed,

or is known, the case is different as regards the distance between thesurface of the table and the spot film device. The spot film device,containing the film, extends horizontally above the top of the table andabove the body of a patient lying thereon, and is adjustable up and downin accordance with the thickness of the patients body or of thefpart tobe examined. The spot film device must be adjusted close against thebody and hence the distance from the film to the surface of the tableand to the focal spot of the tube is variable, over a considerablerange.

In view of the foregoing it is impossible to accurately set thekilo-voltage selector prior to examination of the patient. This must bedone with the patienton the table. After he has been adjusted properly,usually by fluoroscopic examination, and the operator is ready to makethe radiograph, it is desirable to be able to quickly determine thekilo-voltage to use so that the exposure can be made before the positionis disturbed.

The problem thus presented is solved in accordance with the invention byprovision of an arrangement which includes a scale on the spot filmtower and an index movable with the spot film device for cooperationwith the scale. The scale is calibrated in accordance with kilo-volts tobe added to or subtracted from a predetermined standard kilo-voltagewhich is known to be suit:- able for the average body thickness.

The invention will be described more in detail in the specificationwhich follows, reference being had to the accompanying drawing, inwhich- Fig. 1 is a side elevation of an X-ray table embodying theinvention;

Fig. 2 is an enlarged view of the scales and index member; and

--Fig. 3 shows the compression cone which may be used with the spot filmdevice.

Referring to the drawing, thereference char-- acter l0 indicates anX-ray table of known construction, having the base I upon which it ismounted in known manner." The table comprises side members I2 and I3which are secured together in spaced relation, and a top H! which issupported a short distance above the side memhere,

The reference character l5 indicates the fluoroscopic carriage andshutter assembly, which is supported on the side members l2 and I3 bymeans of ball bearings and steel tracks (not shown) and is movablelengthwise of the table. Depending from the carriage is a lead linedcone H5 at the lower end of which the X-ray tube I1. is supported in anysuitable manner.

The carriage l5 includes a part which extends to the rear of the tablebeneath the top M, where it is attached to and supports the verticalspot film device tower IS. The spot film device is indicated at I9 andmay be similar to the device shown in U. S. Patent No. 2,184,962,granted December 26, 1939.

The spot film device is pivotally supported on the elevator 28 and maybe raised to a vertical position where it is out of the way. When in useit extends forward horizontally above the top of the table 'as shown.The elevator 28 is movable up and down on the tower H3 in order toadjust the front of the tower i8 and which carry the.

scales suitably stamped, embossed or printed thereon as shown in Fig. 2.The strip 20 at the right carries the kilo-voltage scale, marked P. K.V. at the top, while strip 2| carries a centimeter scale marked CM.

The index member 22 is preferably made of sheet metal, like the scalestrips 20 and 2|, and

has a forwardly extending part 3ilby means of.

which it is attached to the top of elevator 28.

The index member accordingly moves up and down with the spot film deviceas the latter is adjusted to the patients body. It has two arrowslabeled Cone Compr. andfNo C0mpr., respectively, which cooperate withthe kilovoltage and centimeter scaleson strips 20 and 2|. While thelower arrow is obscured by the spot film device [9 in Fig. 1, it isvisible to the operator looking down on the apparatus from above thepatient, since there is some'space between the rear of the spot filmdevice and the front of the elevator.

Referring to the centimeter scale it will be noted that there is a scaledivision marked AVG. and that the scale is calibrated from 1 to 15toward the bottom and also from 1 to 15 toward the top. Thesecalibrations are in centimeters and make it possible to read directly ifthe body of a patient on the table'is of average thickness or not, andif not, how much it departs in either direction from the averagethickness. When the arrow marked No Compr. is opposite the scaledivision marked AVG. the film is 21 Y downward direction from AVG.

3 centimeters above the table top. This distance has been determined bymeasurements of a large numbe of individuals which show that the averagebody thickness in the stomach region, where spot film radiographs aretaken, is 21 centimeters. If the arrow points to AVG., therefore, afterthe spot film device is adjusted, the operator knows that the patientsbody is of average thickness, and he knows also that the thickness is 21centimeters. If the arrow points to some scale division above or belowaverage, on the other hand, the operator can read directly how much thebody thickness exceeds or is less than the average. In Fig. 2, forexample, the arrow indicates that the body thickness is 5 centimetersless than average.

The information as to body thickness thus supplied is of value incertain techniques, as will be readily understood. If in any case theoperator desires or needs to know the actual distance between the filmand table top he merely has to add r subtract the number of centimetersshown by the arrow or indicator to or from, the value of 21 centimeters.Thus in Fig. 2 the distance indicated is 21 centimeters less 5centimeters, or 16 centimeters.

Referring now to the kilo-voltage scale P. K. V. on the right, thecenter division of the scale is marked AVG, as in the case of thecentimeter scale. Al'solike that scale, the kilo-voltage scale iscalibrated in both an upward and The calibrations are in kilo-volts andby cooperation with the No Compr. arrow indicate to the operator thefrom a standard kilo-voltage in order to obtain the correct kilo-voltagesetting for any given patient.

Further explaining the foregoinggthe operator has a standard techniqueadapted for spot film radiography which has been worked outexperimentally and which depends on theuse of a certain standardkilo-voltage for making a radiograph of a person with average bodythickness. This standard kilo-voltage may. be, for example, 60kilo-volts. -If the body is'thicker than average the kilo-voltage has tobe increased While if it is f thinner than average the kilo-voltageshould be correspondingly reduces- After'the spot film device has beenadjusted properly the No-Compr. arrow shows directly the amount ofnumber of kilo-volts to be added to or subtracted be increased by 6kilo-volts'and that the correct marked Cone Compr. which is used by theoperator to read the kilo-voltage correction at times when the cone isin use. This arrow gives,

readings calling for kilo-voltages which are 10 kilo-volts higher thanthose called for by corresponding readings with the other arrow. Thisvalue depends on the depth of the cone and consequently it is desirableto use the one furnished with the machine or another one having the samedimensions.

The invention having been described that which is believed to benew andfor which-the'pro tection of Letters Patent is desired will be pointed.out in the appended claims.

I claim:

1. In combination, an X-ray table comprising sidev members and a topsupported thereon, a carriage supported on said side members beneathsaid top and movable lengthwise of the table, an X-ray tube supported onsaid carriage beneath said top'and at a predetermined distancetherefrom, a tower supported on said carriage at the, rear of said tableand extending vertically upward above the. top thereof, a spot filmdevice supported on said tower above the table top,

means for adjusting said spot film device up or generally centraldivision markon said'scaleopfposite which said indicator is disposedwhensaid spot film device is adjustedto. apatient of average bodythickness, the position of said division mark being so related tothe-sum of average body thickness and'the distance-between the 'X raytube and table top. that when the indicator is opposite said divisionmark it indicates. a -predetermined average kilo-voltage which isstandard for that conditon, a plurality of other division. marks on saidscal'e extending above and belowsaid'cen trai division mark, andnumeralsassociated with said other division marks, said numerals "havingselected values such that when the indicator-is opposite any one of saidother division mar-ks the associated numeral will'show thenumberof'kilovolts to be added to or subtracted/from said standardkilo-voltage. v V

2; The combination as claimed in claim 1, wherein the spot filmdevice'has a detachable compression cone for insertion between the spotfilm device. and the patients body, and-asecond.

REFERENCES 'CITED The following references are'of recordin the file ofthis patent:

UNITED STATES'PATENTS Number Name Date 47,728 Galdwell; Mar. 19, 19072,329,187 De Lorimier et 'al. Sept. 14.1%3 2,455,522 'RiIlQlEI" Dec.7,;1948 2,455,928

Hawks Dec. 14,1948

